On May 5, one day before Nicholas Wade's new book A Troublesome Inheritance: Genes, Race and Human History came out, I appeared with him in a webinar sponsored by the American Anthropological Association. It was a striking experience. I expected there to be a strong back-and-forth debate about the research on human genetics and how we interpret it, and about human evolution and what we know about it. This was not the case.
Wade argues that there are definable and genetically identifiable groups we can identify and label as biological races in humans today. He would not provide a definition for what he meant by "race" or a specific number of races that we have (he goes back and forth between three, five and seven). Wade relies on a teeny slice of the overall available data on human genetics to support his case. In short, he suggests that believing in biological races (especially African, Caucasian and East Asian) is just common sense. Wade then states that evolved differences in these races are the key explanation for social differences in histories, economies and societies between them -- why "Chinese society differs profoundly from European society, and both are entirely unlike a tribal African society" (p. 123). Wade argues that it is genetic differences and separate evolutionary histories that help us understand why Chinese dynasties lasted so long, why it was so difficult for the U.S.A. to instill democratic social institutions in Iraq after the war and why so many Jews win Nobel prizes.
In making these assertions Wade ignores the majority of data and conclusions from anthropology, population genetics, human biology and evolutionary biology. In the webinar he was even adamant about refusing to even interact with any data or analyses that in any way demonstrated that his simplistic assertions were wrong. Wade just ducked every question that challenged him.
Wade's approach is particularly dangerous because his argument is that he is just a defender of scientific truth and that a cabal of left-leaning academics is obfuscating reality with oppressive, even fascistic, denials of the truth about race. Unfortunately, he is either ignorant of the actual data and diversity of research or he is willfully avoiding them.
Wade's book misrepresents genetic and evolutionary data; his pronouncements about race and what it means are sweeping the Internet with glowing reviews from true believers. Charles Murray (co-author of The Bell Curve) wrote a glowing review in The Wall Street Journal championing Wade as the voice of reasons against a sea of left-leaning, lying academics. Jared Taylor of the hyper-conservative and openly racist magazine American Renaissance congratulated Wade on his blow to the supposedly fascist left that is academia.
There is one place I do agree with Wade: We need to get together and, fearlessly and accessibly, tackle what the social and biological sciences actually tell us about genetic variation, race, evolution and why it all matters. Wade does not do this in his book, nor did he do it in our conversations. So to assist in actually getting this going, I offer a few basic bits of information.
Wade makes two assertions that underlie all the rest of his arguments:
- Humans are divided into genetically identified "continental races" (three, five or seven, depending on where you are in the book).
- Significant differences in genetically based social behaviors are observable between these "races" as a result of the last 50,000 (or 15,000) years of human evolution.
He's wrong on both counts.
Let's start with a few core facts about human genetic variation:
- Genes don't do anything by themselves; epigenetics and complex metabolic and developmental systems are at play in how bodies work. The roundworm C. elegans has about 20,000 genes while humans have about 23,000 genes, yet it is pretty obvious that humans are more than 15-percent more complex than roundworms. So while genes matter, they are only a small part of the whole evolutionary picture. Focusing just on DNA won't get you anywhere.
- If you are making a scientific argument about genetic variation, you need to focus on populations -- and be clear about your definitions. Throughout the book, Wade uses the words "cluster," "population," "group," "race," "subrace" and "ethnicity" in a range of ways, with few concrete definitions, and occasionally interchangeably.
- The real question is what human genetic variation actually looks like. Are there five (or three, or seven) "continental" races? No, and here is why:
- Humans all share essentially 100 percent of our genes and 99.9 percent of our variation. So the variation we are interested in involves 0.1 percent of the entire genome. And yes, understanding that variation is important.
- The vast majority of DNA that varies is not in genes themselves and is not shaped by natural selection in the way that Wade suggests it is.
- Most variation is due to gene flow and genetic drift. The further apart two populations are, the more differences they are likely to have.
- Most of the variation in our entire species is found in populations just in Africa. All the variation found in all population outside Africa makes up just a small subset of that variation.
So while different populations vary in some of that 0.1 percent of the genome, this variation does not represent biological "races." For example, when you compare (as Wade does) people from Nigeria, Western Europe and Beijing and Tokyo, you do get some patterned differences, but these populations do not reflect the entire continental areas of Africa, Europe and Asia, respectively. If you compare geographically separated populations within the "continental" areas, you get the exact same kind of variation. Comparing 60 Nigerians, 60 Americans of European descent and 89 people from Beijing and Tokyo gives us the same kind of differences in patterns as does comparing people from Siberia, Tibet and Java, or from Finland, Wales and Yemen, or even from Somalia, Liberia and South Africa -- and none of these comparisons tells us anything about "races."
Identifying a few genetic variants that are more common in some populations in some parts of some continents than they are in other populations in other parts of other continents does not even come close to any biologically valid or intellectually reasonable demonstration of race. In fact, if one uses the common level of genetic differentiation between populations used by zoologists to classify races (called subspecies) in other mammals, humans always show up as just one biological race.
The originators of the computer program most often used to support the argument that humans divide into the continental genetic clusters (which Wade says are "races") comment that their model (called structure) is not well-suited to data shaped by restricted gene flow with isolation by distance (as human genetic variation data on large scales are). They warn that if one does try to apply this model to those data, the inferred value of K (how many clusters emerge) can be rather arbitrary. For example, one article Wade cites shows not three, not five, not seven but 14 clusters, six of which are in Africa alone.
So when Wade states in chapter 5 of his book, "It might be reasonable to elevate the Indian and Middle Eastern groups to the level of major races, making seven in all," he notices a problem: "But then, many more subpopulations could be declared races." But he has a solution: "[T]o keep things simple, the 5-race continent based scheme seems the most practical for most purposes."
Sure, it is practical if your purpose is to maintain the myth that black, white and Asian are really separable biological groups. But if your goal is to accurately reflect what we know about human biological variation, then no, it is a really not practical at all; in fact, it is flat-out wrong. What we know about human genetic variation does not support dividing humans into three or five or seven "races."
What about Wade's take on human evolution? He acknowledges that yes, culture and history are important, but he argues that the real interesting stuff is in genetic influences on social behavior. Culture is a mighty force, he says, but it is the genetic bases for our behavior that "prompt the mind" of peoples toward certain propensities.
In regard to the races (whether it is three, five or seven) and societies, Wade asserts that the differences "stem from the quite minor variations in human social behavior ... that have evolved within each race during its geographical and historical existence." These differences are based on different races' social institutions, which he claims are "largely cultural edifices resting on a base of genetically shaped social behaviors."
Setting aside the fact that these continental races don't actually exist, such a simplistic version of evolution is just not accurate. Let me lay out our current understanding of human evolution:
- Mutation introduces genetic variation, which, in interaction with genetic drift (chance events that change DNA), epigenetic (non-DNA-based changes in the way genes and proteins work) and developmental (biological growth and change over the lifespan) processes, produces biological variation in organisms.
- Gene flow (the movement and mixing of peoples and DNA) moves the genetic variation around, and natural selection (the process identified by Darwin) shapes variation in response to specific constraints and pressures in the environment.
- Organism-environment interaction can result in niche constructions, which can alter the way natural selection operates and create new ecologies.
- In humans, multiple systems of inheritance (genetic, epigenetic, behavioral and symbolic) can all provide information that can influence biological change over time. Social structures, cultural patterns and behavioral actions can impact evolutionary processes, which in turn can affect our bodies and behaviors.
The bottom line is that evolution is not, as Wade would have us believe, simply a process of natural selection shaping our genes. Presenting it as such is highly misleading.
As far as the fossil, archeological and historical record goes, Wade argues that it supports the view of people radiating out of Africa and staying away from one another for as much as 50,000 years. He says on page 74:
People as they spread out across the globe at the same time fragmented into small tribal groups. The mixing of genes between these little populations was probably very limited. Even if geography had not been a formidable barrier, the hunter-gatherer groups were territorial and mostly hostile to strangers. Travel was perilous. Warfare was probably incessant.
He says these groups followed "independent evolutionary paths that led inevitably to the different human populations or races that inhabit each continent."
I don't have the space here to go into all the ways in which this is completely out of touch with what we know from anthropology, archeology, paleoanthropology, sociology and history about the last 50,000 years, but let me just say that Wade's views on human evolution, how evolution works and how societies have changed over time are way off the mark, and there are numerous books, articles and even documentaries that have shown this over and over again for decades.
So where does all of this leave us? Contrary to Wade's assertions, the actual data on human genetic variation and human evolution demonstrate that we do not have multiple continental "races" in humans (currently there is one biological race in our species, Homo sapiens sapiens), that we do not evolve simply by genetic shifts in response to the environment and that we did not spend the last 15,000 to 50,000 years as tiny, isolated bands of paranoid hunter-gatherers. In short, the scientific data clearly demonstrate that Mr. Wade's assertions are unequivocally wrong.
I agree with Wade that we need to talk about race without fear and with clarity. We do need more public discussions on race. But in doing so, we need to accurately represent what the social and biological sciences actually tell us about genetic variation, race and evolution.